2002-2005年上海市两监测点大气污染物变化规律

目的]了解上海市两监测点大气污染物SO2、NO2和PM10的时空变化规律。方法]收集2002-2005年上海市两个环境监测点（A监测点位于市区，B监测点位于郊区）SO2、NO2和PM10的日均浓度，用SPSS11．5软件，采用Wilcoxon秩和检验和Kruskal-Wallis检验分析大气污染物月、季度和年浓度变化规律，用Spearman秩相关分析两监测点污染物之间的相关性。结果]在1、2、3、5、9、10月份，B监测点S02平均浓度均高于A监测点（P〈0．01或P〈0．05）；NO：月平均浓度在7、12月份B监测点高于A监测点（P〈0．01）；除2、3、5月份外，其他月份PM10的平均浓度B监测点均高于A监测点（P〈0．01或P〈0．05）；A、B两监测点大气S02、NO2和PM10浓度的月份变化均呈“V”型分布。在春、秋、冬3季，B监测点S02平均浓度高于A监测点（P〈0．01），夏季NO2平均浓度B监测点高于A监测点（P〈0．05），PM10则4个季节中B监测点的平均浓度均高于A监测点（P〈0．01）。3种污染物的季节变化多表现为冬季严重，夏季轻的特点。从年变化趋势来看，A监测点的SO2污染呈逐年上升的趋势，NO2和PM10则变化不显著；B监测点的NOz浓度变化趋势相对稳定，SO2和PM10则在地方政府的环境综合整治下有所下降。用国家《环境空气质量标准》（GB3095-1996）评价，两监测点3种污染物均存在超标问题，其中超标最严重的是PM10其次是SO2，且B监测点超标问题较A监测点突出。两监测点3种污染物浓度之间有弱相关性，A监测点各污染物间的相关性高于B监测点，尤其是NO2和PM10的相关性较高。结论]两监测点空气质量尚可，B监测点大气SO2、NO2和PM10污染较A监测点严重，3种污染物浓度之间有弱相关性。

Air Pollutants Changes at Two Monitoring Spots of Shanghai, 2002-2005

Objective ] To analyze the time-spatial variation of air pollutants, i.e. SO2, NO2 and PM10, at two monitoring spots of Shanghai from 2002 to 2005. Methods ] Daily average air SO2, NO2 and PM10 levels during 2002 through 2005 from two environmental monitoring spots （spot A in urban district and spot B in suburb district） of Shanghai were collected. The variation of pollutant levels by month, season and year was analyzed by Wilcoxon rank sum test and Krnskal-Wallis test, and the correlation between pollutants in the two sites was analyzed by Spearman rank correlation analysis using SPSS 11.5. Results ] The monthly SO2 level in spot B was higher than that in spot A in January, February, March, May, September, and October （P〈0.01 or P〈0.05）. The monthly NO2 level in spot B was higher than that in spot A in July and December （P〈0.01）. Except February, March and May, the monthly PMIo level in spot B was higher than that in spot A （P〈0.01 or P〈0.05）. The variation of monthly SO2, NO2 and PM10 levels from January to December showed a ＂V＂ shape fluctuation in both spots. The seasonal level of SO2 in spot B was higher than that in spot A in spring, autumn and winter （P 〈0.01）. The seasonal level of NO2 in spot B was higher than that in spot A in summer （P 〈 0.05）. The seasonal level of PM10 in spot B was all higher than that in spot A （P 〈 0.01）. Almost all air pollutant levels in the two spots were higher in winter and lower in summer. From 2002 through 2005, in spot A, air SO2 level was ascending year after year, variations of air PMlo and NO2 was not distinct. As for spot B, variations of air NO2 was not distinct, but air SO2 and PM10 levels were decreasing because of the comprehensive treatment of local government. According to Ambient Air Quality Standard, GB 3095- 1996, the SO2, NO2 and PM10 levels of the two monitoring spots both exceeded limits, especially PM10 followed by SO2, whereas problems in spot B was more serious than that in spot A. There was a weak correlation among the levels of the three air pollutants, which was more stronger in spot A than in spot B, especially the correlation between NO2 and PM10. Conclusion ] Generally, the air quality in the two spots was acceptable. The air pollution in site B was more serious than that in site A, and a weak correlation was observed among air pollutants SO2, NO2 and PM10.